TomTom, the Dutch navigation system maker, on Tuesday lost an estimated €325.7m in market value as investors responded to the company’s profit warning published on Monday.

The company said in a statement that it expects profits to decrease by almost half in 2011 compared to the year before. The drop was attributed to a decline in personal navigation devices, particularly in the US.

“Consumer electronics markets have been weak over recent weeks and this trend is ongoing. The size of the European PND market is broadly as anticipated and for the year as a whole is expected to decline by around 10 percent. The North American PND market is experiencing a faster rate of decline than earlier in the year and we now expect this market to be down by about 30 percent for the year as a whole,” the company said.

It added: “As a result of these developments we now expect full year revenue of between €1,225m and €1,275m and earnings per share of between €0.25 and €0.30. Revenue for Q2 is expected to be between €300m and €310m.”